A snugly worn earpiece could become the latest fertility device to track menstruation and ovulation cycles. The program, known as YONO Fertility Friend, measures BBT, or Basal Body Temperature, along with other hormones. BBT is the lowest resting body temperature that rises and fall over the course of the month, signaling when a woman is most fertile. YONO will track BBT while the patient sleeps and transfer the data to an Android or iPhone device where the user can be read the bio data over morning coffee. The YONO device is available via Kickstarter for a pledge of $99.